Process and composition for controlling weeds

- Mycogen Corp.

Described and claimed are methods and compositions for the control of unwanted vegetation. According to the subject invention, a fatty acid or mixture of fatty acids can be combined with one or more chemical herbicides to achieve synergistic control of a broad range of plants.

Skip to: Description  ·  Claims  ·  References Cited  · Patent History  ·  Patent History
Description
BACKGROUND OF THE INVENTION

Weeds cost farmers billions of dollars annually in crop losses and in the expense of keeping weeds under control. Much of the cost of intertillage of row crops, maintenance of fallow, seedbed preparation, and seed cleaning is chargeable to weed control. Suppression of weeds along highways and railroad right-of-ways, and in irrigation ditches, navigation channels, yards, parks, grounds, and home gardens also is expensive. Ragweed pollen is the source of annual periodic distress to several million hayfever sufferers. Poison ivy, poison oak, poison sumac, nettles, thistles, sandburs, and puncturevine also bring pain to millions. Weeds also serve as hosts for other crop diseases as well as for insect pests.

The losses caused by weeds in agricultural production environments include decrease in crop yield, reduced crop quality, increased irrigation costs, increased harvesting costs, decreased land value, injury to livestock, and crop damage from insects and diseases harbored by the weeds.

Chemical herbicides have provided an effective method of weed control; however, the public has become concerned about the amount of residual chemicals which might be found in food, ground water, and the environment. Stringent new restrictions on the use of herbicides and the elimination of some effective herbicides from the market place could limit economical and effective options for controlling costly weeds. Additionally, the visually apparent phytotoxic effects of some systemic herbicides appear very slowly on the target weeds, so pesticide users often seek methods by which the apparent speed of action of the herbicide is increased.

There is a great need for novel weed control methods which reduce the amount of chemical herbicide necessary to obtain acceptable levels of weed control. Researchers have experimented with various combinations of chemicals as one approach to identify compositions which have desirable herbicidal characteristics. In the rare instance, unexpected activity of the combination of chemicals is obtained. For example, selective control of annual weeds with a composition of fatty acids mixed with ethylmaleimide, colchicine, 2,4-dinitrohalobenzene, or 2,4-dinitrophenol has been described in the Japanese patent abstract JP61106501. It should be noted that the compounds which were mixed with the fatty acids are not known for their agricultural use and, in fact, may be inappropriate for many herbicidal applications. Other abstracts disclosing a variety of fatty acid derivatives with various chemical compounds include JP59199608 (halogen or cyano derivatives of fatty acids with 2-amino 1,2,4-triazole), JP59199609 (halogen or cyano derivative of fatty acid with 3-amino 1,2,4-triazole), and JP59193804 (acetylenic derivative). Unlike the abstracts mentioned above, the current invention pertains to certain combinations of fatty acids and chemical herbicides which can provide broad range or selective herbicidal activity.

BRIEF SUMMARY OF THE INVENTION

This invention concerns novel compositions and methods for selective or non-selective control of plants. We have discovered that application to weeds of a combination of certain chemical herbicides and one or more substituted (or unsubstituted) saturated (or unsaturated) fatty acids (or their salts) results in the effective control of a broad range of plants. The fatty acids of the subject invention can be from about C7 to about C20 and can be, for example, in the epoxide, cyclopropane, methylated, or hydroxylated forms. The fatty acids of the subject invention can be represented by the following formula:

R.sub.1 Y.sub.1 Y.sub.2 COOR.sub.2

wherein

R.sub.1 =C6 to C19 saturated or unsaturated hydrocarbon, or an epoxide, or cyclopropane thereof

Y.sub.1 =H, C1-C5 hydrocarbon, or hydroxyl at any position along R.sub.1

Y.sub.2 =H, C1-C5 hydrocarbon, or hydroxyl at any position along R.sub.1

R.sub.2 =H, or salt.

Specifically exemplified herein are saturated fatty acids of length C7 to C11 in combination with chemical herbicides. The use of the compositions described here, when used in the proportions and application rates set forth more fully hereinafter, results in an unexpected, enhanced herbicidal effect.

The herbicides used according to the subject invention can be systemic herbicides. In one preferred embodiment of the invention, the herbicides may be systemic herbicides with slow uptake rates. The herbicides may or may not be selective. Therefore, using the compositions and procedures of the subject invention, it is possible to achieve enhanced selective control of weeds or enhanced broad range control.

The composition of the present invention comprises a mixture of components wherein said mixture is sufficiently active so that application of the composition enables utilization of reduced amounts of each of the active ingredients while still providing effective weed control. Additionally, application of the prescribed combination of fatty acids and a systemic chemical herbicide often reduces the time required for systemic phytotoxic symptoms to appear on the target weed.

Since the level of weed control obtained following application of the prescribed mixture is generally much superior to that obtained following application of either active component alone, the practice of the present invention provides a desirable economic advantage to the user. Furthermore, the reduction in the amount of chemicals introduced into the environment is an additional advantageous element of the subject invention. Advantageously, the compositions of the subject invention can provide broad range non-selective herbicidal activity. The compositions of the subject invention may also be used to obtain selective control of weeds.

DETAILED DESCRIPTION OF THE INVENTION

The fatty acids used according to the subject invention can be unsubstituted, or substituted, saturated, or unsaturated, fatty acids (or their salts), of about C7 to about C20. Specifically exemplified are fatty acids of length C7 to C11, as typified by, but not limited to, decanoic acid or nonanoic acid. The fatty acid component of the subject invention may be a single fatty acid or a mixture of two or more fatty acids.

A variety of different chemical herbicides can be used alone or in combination according to the subject invention. The specific herbicides which should be used for a given application can be readily ascertained by a person skilled in the art. Following is a list of herbicides which may be used according to the subject invention.

  ______________________________________                                    

     CHEMICAL HERBICIDE FAMILIES AND EXAMPLES                                  

     HERBICIDE           EXAMPLE                                               

     ______________________________________                                    

     1.  Phenoxy acids (acids, esters, salts)                                  

                             2,4-D, MCPA, Dichlorprop                          

     2.  Benzoic acid        Dicamba                                           

     3.  Aryloxy phenoxypropionate (acids,                                     

                             Fluazifop, Dichlofop                              

         esters, salts)                                                        

     4.  Sulfonyl ureas (acids, esters)                                        

                             Chlorimuron, Bensulfuron                          

     5.  Imidazilinones      Imazethapyr                                       

     6.  Bipyridillium       Paraquat                                          

     7.  Diphenyl ether (acids, salts)                                         

                             Acifluorfen, Fomesafen                            

     8.  Cyclohexanedione    Sethdoxydim, Cycloxydim,                          

                             Clethodim                                         

     9.  Methane arsonate    MSMA (Methylarsonic acid)                         

     10. Triazine            Atrazine, Cyanazine                               

     11. Aliphatic carboxylic acids                                            

                             Dalapon                                           

     12. Benzonitrile        Bromoxynil                                        

     13. Carbamate           Barban                                            

     14. Thiocarbamate       Benthiocarb, Triallate                            

     ______________________________________                                    

     OTHER CHEMICAL HERBICIDES                                                 

     PYRAZON   GLYPHOSATE  PICHLORAM  METRIBUZIN                               

     GLUFOSINATE                                                               

               CLOPYRALID  BENTAZON                                            

     DESMEDIPHAM                                                               

               QUINCLORAC  AMITROLE   PHENMEDI-                                

     TRICLOPYR ETHIOZIN               PHAM                                     

     ______________________________________                                    

Herbicides other than those which are specifically listed above may also be used according to the subject invention. In one preferred embodiment of this invention, a fatty acid is combined with one or more systemic foliar herbicides with slow uptake characteristics. Specifically, the compositions of the subject invention may advantageously comprise a herbicide from one of the following families: phenoxy acids, aryloxy phenoxypropionates, cyclohexanediones, sulfonyl ureas, and imidazilinones. Of these families, imidazilinones and sulfonyl ureas are particularly advantageous. A further preferred embodiment is the use of a fatty acid with glyphosate. This combination has shown substantial synergy as described in the examples below.

Specific examples of the chemical herbicides which can be used together with the fatty acid in the composition of the subject invention include, but are not limited to, glyphosate (N-[phosphonomethyl]glycine, isopropylamine salt), imazapyr ([.+-.],-2-[4,5-dihydro-4-methyl-4-[1-methylethyl]-5-oxo-1H-imidazol-2-yl] -3-pyridine carboxylic acid), sethoxydim (2-[1-[ethoxyimino]butyl]-5-[2-[ethyl-thio]propyl]-3-hydroxy-2-cyclohexen- 1-one), or paraquat (1,1'-dimethyl-4,4'-bipyridinium dichloride), used alone or optionally with agricultural adjuvants with which the herbicides are normally admixed.

One embodiment of the present invention consists of the application of a tankmix of a fatty acid and chemical herbicide. A further embodiment contemplates sequential application of a fatty acid and a chemical herbicide. The process of the subject invention is illustrated in the examples which follow. These examples demonstrate the enhanced synergistic effects achieved through the use of sub-herbicidally effective application rates of the herbicide glyphosate in combination with the fatty acid, nonanoic acid.

Following are examples which illustrate procedures, including the best mode, for practicing the invention. These examples should not be construed as limiting. All percentages are by weight and all solvent mixture proportions are by volume unless otherwise noted.

EXAMPLE 1

A greenhouse trial was carried out to demonstrate the enhanced herbicidal activity obtained following application of a combination of a fatty acid and a chemical herbicide. Purple nutsedge was planted in 4 inch pots in soil-less potting mix (PROMIX) and were cultivated in greenhouses that were maintained at daytime temperatures of 70-90.degree. F., and which were watered by sub-irrigation every other day, until the plants attained the 8 true leaf stage.

The fatty acid herbicide, nonanoic acid, was prepared by diluting the requisite amount of SHARPSHOOTER 80% formulation with sufficient water to provide spray mixes which, when applied by a track sprayer at an application rate of 25 gallons per acre (gpa) would deliver the field equivalent of, respectively, 0.024, 0.488, 0.976, and 1.952 pounds per acre (lb/acre) of the active ingredient. The herbicide glyphosate, was prepared by diluting the requisite amount of commercial ROUNDUP 4 L formulation with sufficient water to provide a spray mix which, when applied at an application rate of 25 gpa by a track sprayer, would deliver the field equivalent of 1.0 (lb/acre) of the active isopropyl amine salt. Additional spray mixes were made up accordingly containing the respective fatty acid in descending order of concentration as set forth above, thus providing a series of dilutions of compositions containing both types of active ingredients in combination.

Purple nutsedge plants were treated with the aforedescribed spray mixes and appropriate untreated checks in treatment groups consisting of 12 plants each, with a total of 4 replications of a treatment within the test. Following application of the spray mixes at a rate of 25 gpa, the plants were removed to the greenhouse and maintained under good growing conditions for the duration of the test period.

Herbicidal effects were assessed at the indicated days after treatment (DAT) over a time period of 6-27 DAT. The weed control ratings ascertained the extent of control, i.e. reduction in growth, obtained and scored on the basis of 0 to 100 where 100 represents kill of the plants and 0 represents no reduction in growth, as compared to the untreated check. The individual ratings on the four treatment replications were averaged to obtain the average percent control for each particular treatment

The results of these tests, indicating evaluations at 6, 14 and 27 DAT are indicated in Table 1. Also shown in Table 1 is the extent of control expected by a combination of herbicides, as based on their respective activities individually. This expected level of control was calculated according to the well known equation: ##EQU1## where X=% control by the fatty acid alone and Y=% control by the glyphosate alone (Colby, S. R. (1966) "Calculating synergistic and antagonistic responses of herbicide combinations," Weeds 15:20-22).

                                    TABLE 1                                 

     __________________________________________________________________________

                        Control of 8 Leaf Nutsedge in a Greenhouse Trial       

                        Days after treatment                                   

                        6              14             27                       

                                Percent Incre-  Percent In-   Percent In-      

     Nonanoic                                                                  

          Glypho-                                                              

              Approx. wt. ratio, No-                                           

                        Expect-                                                

                            Actual                                             

                                ase over Ex-                                   

                                       Expected                                

                                            Actual                             

                                                crease over                    

                                                      Expect-                  

                                                          Actual               

                                                              crease over      

     acid sate                                                                 

              nanoic acid to Glyph-                                            

                        ed Con-                                                

                            Control                                            

                                pected Con-                                    

                                       Control                                 

                                            Control                            

                                                Expected                       

                                                      ed Con-                  

                                                          Control              

                                                              Expected         

     lb/acre                                                                   

          lb/acre                                                              

              osate     trol %                                                 

                            %   trol   %    %   Control                        

                                                      trol %                   

                                                          %   Control          

     __________________________________________________________________________

     0.244                                                                     

          --  --        --  0   --     --   0   --    --  0   --               

     0.488                                                                     

          --  --        --  0   --     --   0   --    --  0   --               

     0.976                                                                     

          --  --        --  0   --     --   0   --    --  5   --               

     1.952                                                                     

          --  --        --  0   --     --   4   --    --  8   --               

     --   1.0 --        --  25  --     --   83  --    --  82  --               

     0.244                                                                     

          1.0 0.244:1   25  64  156    83   88   6    82  100 22               

     0.488                                                                     

          1.0 0.488:1   25  56  124    83   93  12    82  100 22               

     0.976                                                                     

          1.0 0.976:1   25  55  120    83   91  10    83  100 21               

     1.952                                                                     

          1.0 1.952:1   25  74  196    84   96  15    83  100 20               

     __________________________________________________________________________

EXAMPLE 2

Additional greenhouse tests were performed to evaluate mixtures of fatty acids and herbicides on mature weeds and at reduced herbicidal rates. Purple nutsedge was grown as described in Example 1 except that it was allowed to reach the 11 leaf stage. Spray mixes of SHARPSHOOTER 80% were prepared to the same concentrations and by the same methods as described in Example 1. Spray mixes of ROUNDUP 4 L were prepared by the methods described above, but at such a concentration that, when sprayed at an application rate of 25 gpa by a track sprayer, they would deliver the field equivalent of 0.5 (lb/acre) of the active isopropyl amine salt. Additional spray mixes were made up accordingly containing the respective fatty acid in descending order of concentration as set forth above together with glyphosate at the concentration set forth above, thus providing a series of dilutions of compositions containing both types of active ingredients in combination.

Purple nutsedge plants were treated with the aforedescribed spray mixes and appropriate untreated checks in treatment groups consisting of 12 plants each, with a total of 3 replications of a treatment within the test. Following application of the spray mixes at a rate of 25 gpa, the plants were removed to the greenhouse and maintained under good growing conditions for the duration of the test period.

Herbicidal effects were assessed as percent control in the manner described above at 21 and 56 DAT The individual ratings on the three treatment replications were averaged to obtain the average percent control for each particular treatment.

The results of these tests are indicated in Table 2. Also shown in Table 2 is the extent of control expected by a combination of herbicides, as calculated in the manner described above.

                                    TABLE 2                                 

     __________________________________________________________________________

                          Control of 11 Leaf Nutsedge in a Greenhouse Trial    

                          Days after treatment                                 

                          21                   56                              

                                        Percent In-          Percent In-       

                  Approx. wt. ratio,    crease over          crease over       

     Nonanoic acid                                                             

            Glyphosate                                                         

                  Nonanoic acid to                                             

                          Expected Con-                                        

                                 Actual Control                                

                                        Expected Con-                          

                                               Expected Con-                   

                                                      Actual                   

                                                             Expected Con-     

     lb/ac  lb/ac Glyphosate                                                   

                          trol % %      trol   trol % %      trol              

     __________________________________________________________________________

     0.244  --    --      --     1      --     --     9      --                

     0.488  --    --      --     0      --     --     10     --                

     0.976  --    --      --     1      --     --     13     --                

     1.952  --    --      --     3      --     --     9      --                

     --     0.5   --      --     38     --     --     85     --                

     0.244  0.5   0.488:1 39     71     84     86     100    16                

     0.488  0.5   0.976:1 38     76     100    87     96     11                

     0.976  0.5   1.952:1 39     73     89     87     98     13                

     1.952  0.5   3.904:1 40     60     51     86     90      4                

     __________________________________________________________________________

EXAMPLE 3

A series of field tests were performed to show the effect of fatty acids in combination with chemical herbicides on mature purple nutsedge and sicklepod. Purple nutsedge and sicklepod were grown to the 8 leaf and 6 leaf stage, respectively, in field plots approximately 16.5 square feet in area. Spray mixes of the fatty acid herbicide, nonanoic acid, was prepared by diluting the requisite amount of SHARPSHOOTER 80% formulation with sufficient water to provide spray mixes which, when applied by a gas-pressurized backpack sprayer at an application rate of 10 gallons per acre (gpa) would deliver to the field 0.975, 1.950 and 2.925 pounds per acre (lb/acre) of the active ingredient. The herbicide glyphosate was prepared by diluting the requisite amount of commercial RODEO (5.4 L) formulation with sufficient water to provide a spray mix which, when applied at an application rate of 10 gpa, would deliver to the field 0.5, 1.0 and 1.5 lb/acre of the active isopropyl amine salt. To all glyphosate spray mixes was admixed the surfactant X-77 (Union Carbide) at a final concentration of 0.25% (v/v) in the solutions, as recommended by the manufacturer. Additional spray mixes were made up accordingly containing the respective fatty acid in descending order of concentration as set forth above, thus providing a series of dilutions of compositions containing both types of active ingredients in combination.

The spray mixes, and appropriate checks, were applied to the field plots in a randomized complete block design with 3 replications per treatment. The plants received overhead irrigation every other day during the duration of the experiment. The herbicidal effect of the spray mixes on purple nutsedge, measured as described in Example 1 above, including the expected control of the combinations, 17 DAT are recorded in Table 3. Also recorded are the effects on sicklepod 10 DAT.

                                    TABLE 3                                 

     __________________________________________________________________________

                          Control of Nutsedge and Sicklepod In a Field Trial   

                          8 Leaf Nutsedge 17 days after treatment              

                                               6 Leaf Sicklepod 10 Days after  

                                               treatment                       

                                        Percent In-          Percent In-       

                  Approx. wt. ratio,    crease over          crease over       

     Nonanoic acid                                                             

            Glyphosate                                                         

                  Nonanoic acid to                                             

                          Expected Con-                                        

                                 Actual Control                                

                                        Expected Con-                          

                                               Expected Con-                   

                                                      Actual                   

                                                             Expected Con-     

     lb/ac  lb/ac Glyphosate                                                   

                          trol % %      trol   trol % %      trol              

     __________________________________________________________________________

     0.975  --    --      --     0      --     --     0      --                

     1.950  --    --      --     0      --     --     3      --                

     2.925  --    --      --     0      --     --     5      --                

     --     0.5   --      --     57     --     --     23     --                

     --     1.0   --      --     70     --     --     37     --                

     --     1.5   --      --     77     --     --     40     --                

     0.975  0.5   1.95:1  57     67     18     23     37      85               

     0.975  1.0   0.975:1 70     85     21     37     77     108               

     0.975  1.5   0.65:1  77     85     10     40     93     151               

     1.950  0.5    3.9:1  57     67     18     37     27      21               

     1.950  1.0   1.95:1  70     85     21     39     77      98               

     1.950  1.5    1.3:1  77     88     14     40     98     152               

     2.925  0.5   5.85:1  57     57      0     40     33     neg.              

     2.925  1.0   2.925:1 70     87     24     42     83      98               

     2.925  1.5   1.95:1  77     83      8     43     98     128               

     __________________________________________________________________________

EXAMPLE 4

The effect of a combination of nonanoic acid and glyphosate on 5 species of plants grown under field conditions was determined. The five plant species, and their growth stage at the time of treatment, were: velvetleaf (3 leaf), corn (4 leaf), barnyardgrass (4 leaf), sicklepod (3 leaf), and nutsedge (2-3 leaf). Spray mixes of nonanoic acid were prepared by diluting the requisite amount of SHARPSHOOTER 80% formulation with sufficient water to provide spray mixes which, when applied by a pressurized backpack sprayer at an application rate of 25 gpa would deliver to the field 1.95 lb/acre of the active ingredient. The herbicide glyphosate was prepared by diluting the requisite amount of commercial RODEO (5.4 L) formulation with sufficient water to provide a spray mix which, when applied at an application rate of 25 gpa, would deliver to the field 0.169, 0.338 and 0.675 lb/acre of the active isopropyl amine salt. Additional spray mixes were made up accordingly containing the glyphosate in descending order of concentration as set forth above together with nonanoic acid at the concentration set forth above, thus providing a series of dilutions of compositions containing both types of active ingredients in combination.

The spray solutions were applied to a field plot approximately 16.5 square feet in area; there were 2 replications per treatment. Herbicidal effect was assessed as described in Example 1. The results on purple nutsedge and sicklepod at 14 and 28 DAT are tabulated in Tables 4 and 5, respectively, along with expected values of the combinations calculated according to the method described in Example 1. The results on velvetleaf, corn and barnyardgrass at one rate of the combination are tabulated in Table 6.

                                    TABLE 4                                 

     __________________________________________________________________________

                          Control of Nutsedge in a Field Trial                 

                          14 days after treatment                              

                                               28 Days after treatment         

                                        Percent In-          Percent In-       

                  Approx. wt. ratio,    crease over          crease over       

     Glyphosate                                                                

           Nonanoic acid                                                       

                  Nonanoic acid to                                             

                          Expected Con-                                        

                                 Actual Control                                

                                        Expected Con-                          

                                               Expected Con-                   

                                                      Actual                   

                                                             Expected Con-     

     lb/ac lb/ac  Glyphosate                                                   

                          trol % %      trol   trol % %      trol              

     __________________________________________________________________________

     0.169 --     --      --     0      --     --     0      --                

     0.338 --     --      --     13     --     --     0      --                

     0.675 --     --      --     28     --     --     0      --                

     --    1.95   --      --     0      --     0      0      --                

     0.169 1.95   0.087:1  0     20     .infin.                                

                                               0      35     .infin.           

     0.338 1.95   0.173:1 13     33     154    0      45     .infin.           

     0.675 1.95   0.346:1 28     50      79    0      70     .infin.           

     __________________________________________________________________________

                                    TABLE 4                                 

     __________________________________________________________________________

                          Control of Sicklepod in a Field Trial                

                          14 days after treatment                              

                                               28 Days after treatment         

                                        Percent In-          Percent In-       

                  Approx. wt. ratio,    crease over          crease over       

     Glyphosate                                                                

           Nonanoic acid                                                       

                  Nonanoic acid to                                             

                          Expected Con-                                        

                                 Actual Control                                

                                        Expected Con-                          

                                               Expected Con-                   

                                                      Actual                   

                                                             Expected Con-     

     lb/ac lb/ac  Glyphosate                                                   

                          trol % %      trol   trol % %      trol              

     __________________________________________________________________________

     0.169 --     --      --     0      --     --     5      --                

     0.338 --     --      --     13     --     --     12     --                

     0.675 --     --      --     18     --     --     15     --                

     --    1.95   --      --     10     --     --     10     --                

     0.169 1.95   0.087:1 10     30     200    15     30     107               

     0.338 1.95   0.173:1 22     30     38     21     45     116               

     0.675 1.95   0.346:1 26     45     72     24     55     134               

     __________________________________________________________________________

                                    TABLE 6                                 

     __________________________________________________________________________

                        Control of Velvetleaf, Corn & Barnyardgrass in a Field 

                        Trial                                                  

                        14 Days after treatment                                

                        Velvetleaf     Corn           Barnyardgrass            

                                Percent In-     Percent In-   Percent In-      

     Glypho-  Approx. wt. ratio, No-                                           

                        Expect-                                                

                            Actual                                             

                                crease over                                    

                                       Expected                                

                                            Actual                             

                                                crease over                    

                                                      Expect-                  

                                                          Actual               

                                                              crease over      

     sate                                                                      

         Nonanoic                                                              

              nanoic acid to Glyph-                                            

                        ed Con-                                                

                            Control                                            

                                Expected Co-                                   

                                       Control                                 

                                            Control                            

                                                Expected                       

                                                      ed Con-                  

                                                          Control              

                                                              Expected         

     lb/ac                                                                     

         acid lb/ac                                                            

              osate     trol %                                                 

                            %   ntrol  %    %   Control                        

                                                      trol %                   

                                                          %   Control          

     __________________________________________________________________________

     0.169                                                                     

         --   --        --   3  --     --   10  --    --  13  --               

     --  1.95 --        --  20  --     --   25  --    --  18  --               

     0.169                                                                     

         1.95 0.087:1   22  85  279    33   80  146   29  70  144              

     __________________________________________________________________________

EXAMPLE 5

A field study examined the effect of application of a mixture of nonanoic acid and glyphosate on control of common oats. Common oats were grown to the 5 leaf stage in field plots of approximately 80 square feet area. Nonanoic acid was prepared in a similar manner as described above to yield spray mixes that would deliver to the field, when applied at a rate of 20 gpa, 0.975, 1.95 and 3.9 lb/acre of the active ingredient. Glyphosate was prepared by diluting the requisite amount of the LAWN AND GARDEN (1.6 L) formulation with water to obtain a spray mix which, when applied at a rate of 20 gpa, would deliver to the field 0.10 and 0.20 lb/acre of isopropylamine salt of the active ingredient. Additional spray mixes were made up accordingly containing the glyphosate in descending order of concentration as set forth above together with nonanoic acid at the concentration set forth above, thus providing a series of dilutions of compositions containing both types of active ingredients in combination.

The spray mixes, along with the appropriate checks, were applied to the plants with 3 replications of each treatment. The herbicidal effects 14 DAT were determined as described in Example 1 and are recorded in Table 7.

                TABLE 7                                                     

     ______________________________________                                    

                Approx.                                                        

                       Control of Common Oats 14 DAT                           

                      wt.                    Percent                           

                      ratio,                 increase                          

     Nonanoic         nonanoic Expected      over                              

     acid   Glyphosate                                                         

                      acid to  %      Actual %                                 

                                             Expected                          

     lb/acre                                                                   

            lb/acre   glyphosate                                               

                               control                                         

                                      control                                  

                                             Control                           

     ______________________________________                                    

      0.975 --        --       --     0      --                                

     1.95   --        --       --     0      --                                

     3.90   --        --       --     0      --                                

     --     0.10      --       --     60     --                                

      0.975 0.10       9.75:1  60     78     30                                

     1.95   0.10      19.5:1   60     85     42                                

     3.90   0.10      39.0:1   60     94     57                                

     ______________________________________                                    

EXAMPLE 6

A field trial showing the effect of a mixture of nonanoic acid and glyphosate on control of quackgrass and vetch was performed. The field grown quackgrass and vetch were at 9 and 8 inches tall, respectively, at the time of application. Nonanoic acid spray solutions were prepared as described previously to yield solutions which, when applied at a rate of 30 gpa, would deliver to the field 1.95, 4.90, 5.85, and 7.80 lb/acre of the active ingredient. Glyphosate spray solutions were prepared as in Example 5 from the LAWN AND GARDEN (1.6 L) formulation to yield spray solutions which, when applied at a rate of 30 gpa, would deliver to the field 0.125, 0.25, and 0.50 lb/acre of the isopropylamine salt of the active ingredient. Additional spray mixes were made up accordingly containing the glyphosate in descending order concentration as set forth above together with nonanoic acid at the concentration set forth above, thus providing a series of dilutions of compositions containing both types of active ingredients in combination.

The spray mixtures were applied to field plots of approximately 80 square feet total area and each treatment was replicated 3 times. The herbicidal effects of the mixtures 20 DAT on vetch, measured as described in Example 1, are recorded in Table 8. The herbicidal effect of the mixture at one combination of rates on quackgrass at times from 5-34 DAT are recorded in Table 9.

                TABLE 8                                                     

     ______________________________________                                    

                Approx.                                                        

                       Control of Vetch 20 DAT                                 

                      wt.                    Percent                           

                      ratio,                 increase                          

     Nonanoic         nonanoic Expected      over                              

     acid   Glyphosate                                                         

                      acid to  %      Actual %                                 

                                             Expected                          

     lb/acre                                                                   

            lb/acre   glyphosate                                               

                               control                                         

                                      control                                  

                                             Control                           

     ______________________________________                                    

     1.95   --        --       --     2      --                                

     3.90   --        --       --     7      --                                

     5.85   --        --       --     25     --                                

     7.80   --        --       --     30     --                                

     --      0.125    --       --     10     --                                

     --     0.25      --       --     35     --                                

     --     0.50      --       --     47     --                                

     1.95    0.125    15.6:1   12     13     10                                

     3.90    0.125    31.2:1   16     32     96                                

     5.85    0.125    46.8:1   33     73     125                               

     7.80    0.125    62.4:1   37     83     124                               

     1.95   0.25       7.8:1   36     32     neg.                              

     3.90   0.25      15.6:1   40     58     47                                

     5.85   0.25      23.4:1   51     80     56                                

     7.80   0.25      31.2:1   55     80     47                                

     1.95   0.50       3.9:1   48     72     50                                

     3.90   0.50       7.8:1   51     77     52                                

     5.85   0.50      11.7:1   60     83     38                                

     7.80   0.50      15.6:1   63     92     46                                

     ______________________________________                                    

                                    TABLE 9                                 

     __________________________________________________________________________

                        Control of Quackgrass a Field Triel                    

                        Days after treatment                                   

                        5              20             34                       

                                Percent Incre-  Percent In-   Percent In-      

     Nonanoic                                                                  

          Glypho-                                                              

              Approx. wt. ratio, No-                                           

                        Expect-                                                

                            Actual                                             

                                ase over Ex-                                   

                                       Expected                                

                                            Actual                             

                                                crease over                    

                                                      Expect-                  

                                                          Actual               

                                                              crease over      

     acid sate                                                                 

              nanoic acid to Glyph-                                            

                        ed Con-                                                

                            Control                                            

                                pected Con-                                    

                                       Control                                 

                                            Control                            

                                                Expected                       

                                                      ed Con-                  

                                                          Control              

                                                              Expected         

     lb/acre                                                                   

          lb/acre                                                              

              osate     trol %                                                 

                            %   trol   %    %   Control                        

                                                      trol %                   

                                                          %   Control          

     __________________________________________________________________________

     7.80 --  --        --  17  --     --   20  --    --   0  --               

     --    0.125                                                               

              --        --  0   --     --   10  --    --  13  --               

     --   0.25                                                                 

              --        --  0   --     --   33  --    --  60  --               

     --   0.50                                                                 

              --        --  0   --     --   87  --    --  77  --               

     7.80  0.125                                                               

              62.4:1    17  38  124    28   82  193   13  57  338              

     7.80 0.25                                                                 

              31.2:1    17  27   59    46   85   83   60  78  30               

     7.80 0.50                                                                 

              15.6:1    17  35  100    90   93   4    77  90  17               

     __________________________________________________________________________

It should be understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and the scope of the appended claims.

Claims

1. An agricultural composition for controlling weeds, said composition comprising a first ingredient which is a monocarboxylic acid having about seven to about twenty carbon atoms, or a salt thereof, and a second ingredient that is a systemic chemical herbicide that inhibits an acetolactate synthase.

2. The composition, according to claim 1, wherein said chemical herbicide is selected from the group consisting of imazethapyr, imazapyr, bensulfuron, and chlorimuron.

3. The composition, according to claim 1, wherein said chemical herbicide is imazethapyr.

4. The composition, according to claim 1, wherein said first ingredient can be represented by the following formula:

R.sub.1 =C6 to C19 saturated or unsaturated hydrocarbons, or an epoxide, or cycloprane thereof
Y.sub.1 =H, C1-C5 hydrocarbon, or hydroxyl at any position along R.sub.1
Y.sub.2 =H, C1-C5 hydrocarbon, or hydroxyl at any position along R.sub.1
R.sub.2 =H, or salt.

5. The composition, according to claim 1, wherein said first entity is nonanoic acid.

6. The composition, according to claim 1, wherein said first ingredient is nonanoic acid and said second ingredient is imazethapyr.

7. An agricultural composition for controlling weeds, said composition comprising a first ingredient which is a monocarboxylic acid having about seven to about twenty carbon atoms, or a salt thereof, and a second ingredient which is a chemical herbicide selected from the group consisting of imidazilinones, sulfonyl ureas, and derivatives thereof.

8. The composition, according to claim 7, wherein said first ingredient can be represented by the following formula:

R.sub.1 =C6 to C19 saturated or unsaturated hydrocarbon, or an epoxide, or cyclopropane thereof
Y.sub.1 =H, C1-C5 hydrocarbon, or hydroxyl at any position along R.sub.1
Y.sub.2 =H, C1-C5 hydrocarbon, or hydroxyl at any position along R.sub.1
R.sub.2 =H, or salt.

9. The composition, according to claim 7, wherein said monocarboxylic acid or salt comprises from about seven to about eleven carbon atoms.

10. The composition, according to claim 7, wherein said monocarboxylic acid or salt is unsubstituted.

11. The composition, according to claim 7, wherein said monocarboxylic acid or salt is saturated.

12. The composition, according to claim 7, wherein said monocarboxylic acid is decanoic acid.

13. The composition, according to claim 7, wherein said monocarboxylic acid is nonanoic acid.

14. The composition, according to claim 7, wherein said herbicide is a foliar herbicide.

15. The composition, according to claim 7, wherein said chemical herbicide is selected from the group consisting of sulfonyl urea acids and sulfonyl urea esters.

16. The composition, according to claim 15, wherein said chemical herbicide is selected from the group consisting of chlorimuron and bensulfuron.

17. The composition, according to claim 7, wherein said chemical herbicide is an imidazilinone.

18. The composition, according to claim 17, wherein said chemical herbicide is selected from the group consisting of imazethapyr and imazapyr.

19. A method for the control of unwanted vegetation, said method comprising the administration to said vegetation an effective amount of a composition comprising a first ingredient that is a monocarboxylic acid having about seven to about twenty carbons, or a salt thereof, and a second ingredient that is a systemic chemical herbicide that inhibits an acetolactate synthase.

20. The method, according to claim 19, wherein said first ingredient is used at an application rate that, alone, without other active ingredients, would not result in complete control of said weeds.

21. The method, according to claim 19, wherein said first component is applied at a rate less than about 8 lbs./acre.

22. The method, according to claim 19, wherein said chemical herbicide is selected from the group consisting of imazethapyr, imazapyr, bensulfuron, and chlorimuron.

23. The method, according to claim 19, wherein said chemical herbicide is imazethapyr.

24. The method, according to claim 19, wherein said first ingredient can be represented by the following formula:

R.sub.1 =C6 to C19 saturated or unsaturated hydrocarbons, or an epoxide, or cycloprane thereof
Y.sub.1 =H, C1-C5 hydrocarbon, or hydroxyl at any position along R.sub.1
Y.sub.2 =H, C1-C5 hydrocarbon, or hydroxyl at any position along R.sub.1
R.sub.2 =H, or salt.

25. The method, according to claim 19, wherein said first entity is nonanoic acid.

26. The method, according to claim 19, wherein said first ingredient is nonanoic acid and said second ingredient is imazethapyr.

27. A method for the control of unwanted vegetation, wherein said method comprises administering to said vegetation a monocarboxylic acid having about seven to about twenty carbons, or a salt thereof, and a chemical herbicide selected from the group consisting of imidazilinones, sulfonyl ureas, and derivatives thereof.

28. The method, according to claim 27, wherein said monocarboxylic acid, or salt, can be represented by the following formula:

R.sub.1 =C6 to C19 saturated or unsaturated hydrocarbon, or an epoxide, or cyclopropane thereof
Y.sub.1 =H, C1-C5 hydrocarbon, or hydroxyl at any position along R.sub.1
Y.sub.2 =H, C1-C5 hydrocarbon, or hydroxyl at any position along R.sub.1
R.sub.2 =H, or salt.

29. The method, according to claim 27, wherein said monocarboxylic acid or salt has from about seven to about eleven carbons.

30. The method, according to claim 27, wherein said monocarboxylic acid or salt is decanoic acid.

31. The method, according to claim 27, wherein said monocarboxylic acid or salt is nonanoic acid.

32. The method, according to claim 27, wherein said herbicide is a foliar herbicide.

33. The method, according to claim 27, wherein said chemical herbicide is selected from the group consisting of sulfonyl urea acids and sulfonyl urea esters.

34. The method, according to claim 33, wherein said chemical herbicide is selected from the group consisting of chlorimuron and bensulfuron.

35. The method, according to claim 27, wherein said chemical herbicide is selected from the group consisting of imazethapyr and imazapyr.

36. The method, according to claim 27, wherein said chemical herbicide is an imidazilinone.

Referenced Cited
U.S. Patent Documents
2622975 December 1952 Zimmerman et al.
3799758 March 1974 Franz
4134754 January 16, 1979 Hoffmann
4638068 January 20, 1987 Los
4975110 December 4, 1990 Puritch et al.
5035741 July 30, 1991 Puritch et al.
Foreign Patent Documents
0115622 August 1984 EPX
89/03178 April 1989 WOX
92/07467 May 1992 WOX
Other references
  • Japanese Patent No. 59 193 804 issued Nov. 2, 1984 (abstract). Japanese Patent No. 59 199 608 issued Apr. 27, 1983 (abstract). Japanese Patent No. 59 199 609 issued Apr. 28, 1983 (abstract). Japanese Patent No. 59 193 809 issued Apr. 19, 1983 (abstract). Japanese Patent No. 61 106 501 issued Oct. 30, 1984 (abstract). Japanese Patent No. 61 289 004 issued Jun. 18, 1985 (abstract). The Agrochemicals Handbook (1987) 2nd Edition, Hartley and Kidd, editors: The Royal Society of Chemistry, Nottingham, England, pp. A045 and A138. Turner, D.J. (1985) "Effects on glyphosphate performance of formulation, additives and mixing with other herbicides" The Herbicide Glyphosate, Grossbard and Atkinson, editors, pp. 221-240.
Patent History
Patent number: 6034034
Type: Grant
Filed: Feb 28, 1995
Date of Patent: Mar 7, 2000
Assignee: Mycogen Corp. (San Diego, CA)
Inventors: Jerry Caulder (San Diego, CA), R. Hugh Crowley (Oceanside, CA), Paul S. Zorner (La Costa, CA), Steven L. Evans (San Diego, CA)
Primary Examiner: S. Mark Clardy
Law Firm: Saliwanchik, Lloyd & Saliwanchik
Application Number: 8/396,372